<Appendix 5. PID Block>
285
IM 01E21A02-03EN
A5.9 Block Modes
The block mode is defined with the parameter MODE_BLK.
MODE_
BLK
Target
Defines the target mode.
Actual
Indicates the current block mode.
Changes depending on the status of input data and target
contents.
Permitted
Defines constraints of the target mode.
If constraints are not defined here, it becomes impossible to
transition to the mode.
Normal
Defines the normal mode.
There are eight modes for the PID block as shown below.
Block
Mode
Description
ROut
Remote output mode. The mode outputs the value given by ROUT_IN.
RCas
By the remote cascade connection, the setpoint (SP) is received from the
host computer, etc., and results of the PID control calculation processing are
output.
Cas
By the cascade connection, the setpoint (SP) is received from other function
block, and results of the PID control calculation processing are output.
Auto
The PID block carries out automatic control and outputs the result calculated
by the PID control computation.
Man
The block goes into manual mode, and outputs OUT, the value set by the user
manually.
LO
The PID block outputs the operation output value set in TRK_VAL.
IMan
Initialization and manual mode. This mode temporarily interrupts the control
operation. The mode which operates when the initialization and manual
fallback conditions shown in Section A5.14 are met.
O/S
Control calculation processing is carried out. The output of the previous value
is kept.
A5.9.1 Mode Transitions
Destination
Condition
Other Condition
(1)
O/S
If O/S is specified in MODE_BLK.target
(or if O/S is set in target inside the resource block)
(2)
IMan
If the Initialization and manual fallback conditions are met
(Section A5.14)
NOT if condition (1) is met
(3)
LO
If Track Enable is specified in CONTROL_OPTS and the
value of TRK_IN_D is true
NOT if either or both of
conditions (1) and (2) are met
(4)
Man
If MAN is specified in MODE_BLK.target or if IN.status
(input status) is BAD
NOT if any one or more of
conditions (1) to (3) are met
(5)
Auto
If Auto is specified in MODE_BLK.target
- AND -
if IN.status (input status) is other than BAD
NOT if any one or more of
conditions (1) to (3) are met
(6)
Cas
If Cas is specified in MODE_BLK.target
- AND -
if IN.Status (input status) and CAS_IN.Status are other
than BAD
NOT if any one or more of
conditions (1) to (3) are met
(7)
RCas
If RCas is specified in MODE_BLK.target
- AND -
if IN.Status (input status) and RCAS_IN.Status are other
than BAD
NOT if any one or more of
conditions (1) to (3) are met
(8)
ROut
If ROut is specified in MODE_BLK.target
- AND -
if ROUT_IN.status (input status) is other than BAD
NOT if any one or more of
conditions (1) to (3) are met
Note 1: To activate mode transitions to Auto, Cas, RCas, and ROut, the respective target modes
must be permitted beforehand with MODE_BLK.permitted.
